Laboratory Studies of Abnormal Host Defense and Immunoregulatory Diseases

宿主防御异常和免疫调节疾病的实验室研究

• 批准号: 8336358
• 负责人: Kol Zarember
• 金额: $ 19.01万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8336358
• 关键词: Address; Anti-Inflammatory Agents; Anti-inflammatory; Antifungal Agents; Apoptosis; Aspergillosis; Biology; Biomass; Carbohydrates; Cells; Chelating Agents; Collaborations; Complement; Complex; Disease; Generations; Glucosamine; Glucose; Goals; Growth; Host Defense; Human; Immune; Immune system; Infection; Inflammation; Inflammatory; Investigation; Iron; Iron Chelating Agents; Laboratory Study; Lactoferrin; Leukocytes; Leukotriene B4; Lipid A; Lipid Peroxidation; Lipids; Lipopolysaccharides; Mediator of activation protein; Messenger RNA; Metabolism; Methods; MicroRNAs; Microbe; Mus; NADPH Oxidase; National Institute of Diabetes and Digestive and Kidney Diseases; Normal Cell; Organism; Paste substance; Pathogenesis; Pathway interactions; Patients; Play; Property; Prostaglandin D2; Proteins; RNA; Reporting; Research; Resistance; Resolution; Role; Signal Transduction; Therapeutic Intervention; Universities; Vertebral column; antimicrobial peptide; base; cytokine; efficacy testing; histiocyte; immunosuppressed; in vivo; innate immune function; lipid mediator; lipid metabolism; mRNA Expression; mRNA Stability; neutrophil; novel; pathogen; prophylactic; stem; sugar

Iron Chelators as antifungal drugs: Based on our previous years investigations identifying the iron-chelating protein, lactoferrin, as an important host defense against aspergillosis, we have been studying the ability of synthetic iron chelators to inhibit fungal growth. In FY11, we completed our tests of the efficacy of ciclopirox and lactoferrin as invidual prophylactic antifungal drugs in experimental aspergillosis in immunosuppressed WT and in CGD mice (collaboration with June Kwon-Chung (LCID). Host defenses against Granulibacter bethesdensis We have continued to study Granulibacter bethesdensis, a recently described bacterial pathogen of CGD patients. We have found that Granulibacter is remarkably hypostimulatory of the human innate immune system, both in terms of weak activation of the NADPH oxidase and poor stimulation of cytokine secretion. Partial purification and structural characterization of an atypical lipopolysaccharide (LPS) of this organism continue but already indicate a 2,3-diamino-2,3-dideoxy-D-glucose (DAG) lipid A backbone (as opposed to the far more common glucosamine backbone). DAG containing Lipid A have been reported to have many unusual signaling properties. Furthermore, KDO, a core sugar present in most LPS, was not detected. In collaboration with Yossi Shiloach (NIDDK), we developed large-scale growth methods for this slow-growing and low-biomass organism that allowed generation of sufficient cell paste for LPS extraction and pending, high-resolution structural studies (with Russ Carlson at the University of Georgia Complex Carbohydrate Research Center). We have also found that G. bethesdensis is remarkably resistant to complement and antimicrobial peptides and that, unlike most microbes, Granulibacter inhibits neutrophil apoptosis. We are examining the pathways involved in this inhibition and attempting to ascertain whether this plays a role in pathogenesis. MicroRNA expression in normal and CGD neutrophils: Steady-state levels of many mRNAs differ between normal and CGD leukocytes and it is thought that some of the clinically apparent inflammatory and immune problems seen in these patients may stem from these differences. Recently, a group of small regulatory RNA species (miRNA) has been implicated in post-transcriptional fine-tuning of mRNA stability. We hypothesize that some of the inflammatory problems seen in patients with CGD might be due to different expression of miRNA and the subsequent dysregulation of mRNA levels. To address this, we are analyzing miRNA levels in normal and CGD neutrophils by both deep sequencing and microarray approaches. Results of this study are pending and will be compared to known differences in mRNA expression between these cells. Identification of such regulatory circuits may be useful in recognizing (without prior biases) potential targets for therapeutic intervention. Lipid Mediator Biology in CGD: Several studies have demonstrated that metabolism of lipid mediators is deranged in CGD, specifically that in this disease, there is a decrease in prostaglandin D2, and increase in leukotriene B4, and a decrease in lipid peroxidation. In vivo, lipid-laden histiocytes have long been seen in CGD. We are undertaking a systematic study of lipid metabolism in CGD leukocytes to identify what other mediators, for example the newly described resolvin class of anti-inflammatory lipids might be altered in CGD.

铁络合剂作为抗真菌药物： 在前些年研究的基础上，我们发现铁螯合蛋白乳铁蛋白是曲霉病的重要宿主防御系统，我们一直在研究合成铁络合剂抑制真菌生长的能力。在2011财年，我们完成了环吡喃和乳铁蛋白作为预防性抗真菌药物对免疫抑制的WT和CGD小鼠的实验性曲霉病的疗效的测试(与JunKuan-chung(LCID)合作)。 寄主对致密性颗粒菌的防御 我们一直在继续研究Granulibacter bethedensis，一种最近被描述的CGD患者的细菌病原体。我们发现，Granulibacter对人类先天免疫系统具有明显的低刺激作用，无论是在NADPH氧化酶的弱激活方面，还是在对细胞因子分泌的刺激方面。这种生物的非典型脂多糖(LPS)的部分纯化和结构特征仍在继续，但已经表明是2，3-二氨基-2，3-二脱氧-D-葡萄糖(DAG)类A主干(而不是更常见的氨基葡萄糖主干)。据报道，含有Lipid A的DAG具有许多不寻常的信号特性。此外，没有检测到大多数脂多糖中存在的核心糖KDO。在与Yossi Shiloach(NIDDK)的合作下，我们为这种生长缓慢、生物量低的生物开发了大规模生长方法，使其能够产生足够的细胞浆，用于提取脂多糖和正在进行的高分辨率结构研究(与佐治亚大学复杂碳水化合物研究中心的Russ Carlson)。 我们还发现，贝氏革兰氏杆菌对补体和抗菌肽具有显著的抗药性，而且与大多数微生物不同的是，颗粒菌抑制中性粒细胞的凋亡。我们正在研究参与这种抑制的途径，并试图确定这是否在发病机制中发挥作用。 正常和CGD中性粒细胞中microRNA的表达： 在正常和CGD白细胞中，许多mRNAs的稳态水平不同，人们认为在这些患者中出现的一些临床上明显的炎症和免疫问题可能源于这些差异。最近，一组小调节RNA物种(MiRNA)被认为参与了转录后对mRNA稳定性的微调。我们推测，在CGD患者中出现的一些炎症问题可能是由于miRNA的不同表达以及随后的mRNA水平调节失调所致。为了解决这个问题，我们正在通过深度测序和微阵列方法分析正常和CGD中性粒细胞中的miRNA水平。这项研究的结果还在等待中，将与这些细胞之间已知的mRNA表达差异进行比较。识别这样的调节电路可能有助于识别(没有先前的偏见)治疗干预的潜在靶点。 CGD中的脂质调节生物学： 多项研究表明，CGD患者体内脂质代谢紊乱，尤其是前列腺素D2水平降低，白三烯B4水平升高，脂质过氧化水平降低。在体内，在CGD中早就可以看到富含脂质的组织细胞。我们正在对CGD白细胞的脂代谢进行系统的研究，以确定哪些其他介质可能在CGD中发生改变，例如新描述的抗炎性脂类的分解素类。